cregit-Linux how code gets into the kernel

Release 4.8 net/ipv6/esp6.c

Directory: net/ipv6
/*
 * Copyright (C)2002 USAGI/WIDE Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 * Authors
 *
 *      Mitsuru KANDA @USAGI       : IPv6 Support
 *      Kazunori MIYAZAWA @USAGI   :
 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *
 *      This file is derived from net/ipv4/esp.c
 */


#define pr_fmt(fmt) "IPv6: " fmt

#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <linux/scatterlist.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <net/ip6_route.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/icmpv6.h>


struct esp_skb_cb {
	
struct xfrm_skb_cb xfrm;
	
void *tmp;
};


#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))

static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);

/*
 * Allocate an AEAD request structure with extra space for SG and IV.
 *
 * For alignment considerations the upper 32 bits of the sequence number are
 * placed at the front, if present. Followed by the IV, the request and finally
 * the SG list.
 *
 * TODO: Use spare space in skb for this where possible.
 */

static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen) { unsigned int len; len = seqihlen; len += crypto_aead_ivsize(aead); if (len) { len += crypto_aead_alignmask(aead) & ~(crypto_tfm_ctx_alignment() - 1); len = ALIGN(len, crypto_tfm_ctx_alignment()); } len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); len = ALIGN(len, __alignof__(struct scatterlist)); len += sizeof(struct scatterlist) * nfrags; return kmalloc(len, GFP_ATOMIC); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu8477.78%466.67%
kazunori miyazawakazunori miyazawa1715.74%116.67%
steffen klassertsteffen klassert76.48%116.67%
Total108100.00%6100.00%


static inline __be32 *esp_tmp_seqhi(void *tmp) { return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert27100.00%1100.00%
Total27100.00%1100.00%


static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) { return crypto_aead_ivsize(aead) ? PTR_ALIGN((u8 *)tmp + seqhilen, crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu3981.25%133.33%
steffen klassertsteffen klassert714.58%133.33%
arnaldo carvalho de meloarnaldo carvalho de melo24.17%133.33%
Total48100.00%3100.00%


static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) { struct aead_request *req; req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), crypto_tfm_ctx_alignment()); aead_request_set_tfm(req, aead); return req; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu52100.00%1100.00%
Total52100.00%1100.00%


static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, struct aead_request *req) { return (void *)ALIGN((unsigned long)(req + 1) + crypto_aead_reqsize(aead), __alignof__(struct scatterlist)); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu48100.00%1100.00%
Total48100.00%1100.00%


static void esp_output_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; kfree(ESP_SKB_CB(skb)->tmp); xfrm_output_resume(skb, err); }

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PersonTokensPropCommitsCommitProp
herbert xuherbert xu40100.00%2100.00%
Total40100.00%2100.00%

/* Move ESP header back into place. */
static void esp_restore_header(struct sk_buff *skb, unsigned int offset) { struct ip_esp_hdr *esph = (void *)(skb->data + offset); void *tmp = ESP_SKB_CB(skb)->tmp; __be32 *seqhi = esp_tmp_seqhi(tmp); esph->seq_no = esph->spi; esph->spi = *seqhi; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu67100.00%2100.00%
Total67100.00%2100.00%


static void esp_output_restore_header(struct sk_buff *skb) { esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32)); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu26100.00%2100.00%
Total26100.00%2100.00%


static void esp_output_done_esn(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; esp_output_restore_header(skb); esp_output_done(base, err); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu35100.00%2100.00%
Total35100.00%2100.00%


static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) { int err; struct ip_esp_hdr *esph; struct crypto_aead *aead; struct aead_request *req; struct scatterlist *sg; struct sk_buff *trailer; void *tmp; int blksize; int clen; int alen; int plen; int ivlen; int tfclen; int nfrags; int assoclen; int seqhilen; u8 *iv; u8 *tail; __be32 *seqhi; __be64 seqno; /* skb is pure payload to encrypt */ aead = x->data; alen = crypto_aead_authsize(aead); ivlen = crypto_aead_ivsize(aead); tfclen = 0; if (x->tfcpad) { struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); u32 padto; padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached)); if (skb->len < padto) tfclen = padto - skb->len; } blksize = ALIGN(crypto_aead_blocksize(aead), 4); clen = ALIGN(skb->len + 2 + tfclen, blksize); plen = clen - skb->len - tfclen; err = skb_cow_data(skb, tfclen + plen + alen, &trailer); if (err < 0) goto error; nfrags = err; assoclen = sizeof(*esph); seqhilen = 0; if (x->props.flags & XFRM_STATE_ESN) { seqhilen += sizeof(__be32); assoclen += seqhilen; } tmp = esp_alloc_tmp(aead, nfrags, seqhilen); if (!tmp) { err = -ENOMEM; goto error; } seqhi = esp_tmp_seqhi(tmp); iv = esp_tmp_iv(aead, tmp, seqhilen); req = esp_tmp_req(aead, iv); sg = esp_req_sg(aead, req); /* Fill padding... */ tail = skb_tail_pointer(trailer); if (tfclen) { memset(tail, 0, tfclen); tail += tfclen; } do { int i; for (i = 0; i < plen - 2; i++) tail[i] = i + 1; } while (0); tail[plen - 2] = plen - 2; tail[plen - 1] = *skb_mac_header(skb); pskb_put(skb, trailer, clen - skb->len + alen); skb_push(skb, -skb_network_offset(skb)); esph = ip_esp_hdr(skb); *skb_mac_header(skb) = IPPROTO_ESP; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); aead_request_set_callback(req, 0, esp_output_done, skb); /* For ESN we move the header forward by 4 bytes to * accomodate the high bits. We will move it back after * encryption. */ if ((x->props.flags & XFRM_STATE_ESN)) { esph = (void *)(skb_transport_header(skb) - sizeof(__be32)); *seqhi = esph->spi; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); aead_request_set_callback(req, 0, esp_output_done_esn, skb); } esph->spi = x->id.spi; sg_init_table(sg, nfrags); skb_to_sgvec(skb, sg, (unsigned char *)esph - skb->data, assoclen + ivlen + clen + alen); aead_request_set_crypt(req, sg, sg, ivlen + clen, iv); aead_request_set_ad(req, assoclen); seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); memset(iv, 0, ivlen); memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), min(ivlen, 8)); ESP_SKB_CB(skb)->tmp = tmp; err = crypto_aead_encrypt(req); switch (err) { case -EINPROGRESS: goto error; case -EBUSY: err = NET_XMIT_DROP; break; case 0: if ((x->props.flags & XFRM_STATE_ESN)) esp_output_restore_header(skb); } kfree(tmp); error: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu46760.18%1047.62%
martin willimartin willi11514.82%14.76%
steffen klassertsteffen klassert10613.66%29.52%
kazunori miyazawakazunori miyazawa597.60%14.76%
david s. millerdavid s. miller91.16%14.76%
arnaldo carvalho de meloarnaldo carvalho de melo81.03%314.29%
julia lawalljulia lawall70.90%14.76%
jamal hadi salimjamal hadi salim30.39%14.76%
mathias krausemathias krause20.26%14.76%
Total776100.00%21100.00%


static int esp_input_done2(struct sk_buff *skb, int err) { struct xfrm_state *x = xfrm_input_state(skb); struct crypto_aead *aead = x->data; int alen = crypto_aead_authsize(aead); int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); int elen = skb->len - hlen; int hdr_len = skb_network_header_len(skb); int padlen; u8 nexthdr[2]; kfree(ESP_SKB_CB(skb)->tmp); if (unlikely(err)) goto out; if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) BUG(); err = -EINVAL; padlen = nexthdr[0]; if (padlen + 2 + alen >= elen) { net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen + 2, elen - alen); goto out; } /* ... check padding bits here. Silly. :-) */ pskb_trim(skb, skb->len - alen - padlen - 2); __skb_pull(skb, hlen); if (x->props.mode == XFRM_MODE_TUNNEL) skb_reset_transport_header(skb); else skb_set_transport_header(skb, -hdr_len); err = nexthdr[1]; /* RFC4303: Drop dummy packets without any error */ if (err == IPPROTO_NONE) err = -EINVAL; out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu16972.22%650.00%
kazunori miyazawakazunori miyazawa4117.52%18.33%
li rongqingli rongqing166.84%18.33%
david s. millerdavid s. miller41.71%216.67%
joe perchesjoe perches20.85%18.33%
mathias krausemathias krause20.85%18.33%
Total234100.00%12100.00%


static void esp_input_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; xfrm_input_resume(skb, esp_input_done2(skb, err)); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu35100.00%1100.00%
Total35100.00%1100.00%


static void esp_input_restore_header(struct sk_buff *skb) { esp_restore_header(skb, 0); __skb_pull(skb, 4); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu2496.00%150.00%
kazunori miyazawakazunori miyazawa14.00%150.00%
Total25100.00%2100.00%


static void esp_input_done_esn(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; esp_input_restore_header(skb); esp_input_done(base, err); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu35100.00%2100.00%
Total35100.00%2100.00%


static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) { struct ip_esp_hdr *esph; struct crypto_aead *aead = x->data; struct aead_request *req; struct sk_buff *trailer; int ivlen = crypto_aead_ivsize(aead); int elen = skb->len - sizeof(*esph) - ivlen; int nfrags; int assoclen; int seqhilen; int ret = 0; void *tmp; __be32 *seqhi; u8 *iv; struct scatterlist *sg; if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) { ret = -EINVAL; goto out; } if (elen <= 0) { ret = -EINVAL; goto out; } nfrags = skb_cow_data(skb, 0, &trailer); if (nfrags < 0) { ret = -EINVAL; goto out; } ret = -ENOMEM; assoclen = sizeof(*esph); seqhilen = 0; if (x->props.flags & XFRM_STATE_ESN) { seqhilen += sizeof(__be32); assoclen += seqhilen; } tmp = esp_alloc_tmp(aead, nfrags, seqhilen); if (!tmp) goto out; ESP_SKB_CB(skb)->tmp = tmp; seqhi = esp_tmp_seqhi(tmp); iv = esp_tmp_iv(aead, tmp, seqhilen); req = esp_tmp_req(aead, iv); sg = esp_req_sg(aead, req); skb->ip_summed = CHECKSUM_NONE; esph = (struct ip_esp_hdr *)skb->data; aead_request_set_callback(req, 0, esp_input_done, skb); /* For ESN we move the header forward by 4 bytes to * accomodate the high bits. We will move it back after * decryption. */ if ((x->props.flags & XFRM_STATE_ESN)) { esph = (void *)skb_push(skb, 4); *seqhi = esph->spi; esph->spi = esph->seq_no; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi); aead_request_set_callback(req, 0, esp_input_done_esn, skb); } sg_init_table(sg, nfrags); skb_to_sgvec(skb, sg, 0, skb->len); aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); aead_request_set_ad(req, assoclen); ret = crypto_aead_decrypt(req); if (ret == -EINPROGRESS) goto out; if ((x->props.flags & XFRM_STATE_ESN)) esp_input_restore_header(skb); ret = esp_input_done2(skb, ret); out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu21346.51%633.33%
kazunori miyazawakazunori miyazawa9921.62%15.56%
steffen klassertsteffen klassert9721.18%15.56%
daniel ritzdaniel ritz255.46%15.56%
arnaldo carvalho de meloarnaldo carvalho de melo71.53%211.11%
ian morrisian morris40.87%15.56%
david s. millerdavid s. miller40.87%15.56%
hideaki yoshifujihideaki yoshifuji40.87%15.56%
mathias krausemathias krause20.44%15.56%
mitsuru kandamitsuru kanda10.22%15.56%
thomas grafthomas graf10.22%15.56%
patrick mchardypatrick mchardy10.22%15.56%
Total458100.00%18100.00%


static u32 esp6_get_mtu(struct xfrm_state *x, int mtu) { struct crypto_aead *aead = x->data; u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); unsigned int net_adj; if (x->props.mode != XFRM_MODE_TUNNEL) net_adj = sizeof(struct ipv6hdr); else net_adj = 0; return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - net_adj) & ~(blksize - 1)) + net_adj - 2; }

Contributors

PersonTokensPropCommitsCommitProp
benjamin poirierbenjamin poirier3436.17%114.29%
kazunori miyazawakazunori miyazawa2728.72%114.29%
patrick mchardypatrick mchardy1718.09%114.29%
herbert xuherbert xu1313.83%228.57%
mathias krausemathias krause33.19%228.57%
Total94100.00%7100.00%


static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info) { struct net *net = dev_net(skb->dev); const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); struct xfrm_state *x; if (type != ICMPV6_PKT_TOOBIG && type != NDISC_REDIRECT) return 0; x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6); if (!x) return 0; if (type == NDISC_REDIRECT) ip6_redirect(skb, net, skb->dev->ifindex, 0); else ip6_update_pmtu(skb, net, info, 0, 0); xfrm_state_put(x); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
kazunori miyazawakazunori miyazawa9454.65%17.14%
david s. millerdavid s. miller2916.86%214.29%
alexey dobriyanalexey dobriyan148.14%214.29%
steffen klassertsteffen klassert105.81%17.14%
hideaki yoshifujihideaki yoshifuji74.07%17.14%
duan jiongduan jiong52.91%17.14%
jamal hadi salimjamal hadi salim42.33%17.14%
eric dumazeteric dumazet31.74%17.14%
brian haleybrian haley21.16%17.14%
herbert xuherbert xu21.16%17.14%
patrick mchardypatrick mchardy10.58%17.14%
al viroal viro10.58%17.14%
Total172100.00%14100.00%


static void esp6_destroy(struct xfrm_state *x) { struct crypto_aead *aead = x->data; if (!aead) return; crypto_free_aead(aead); }

Contributors

PersonTokensPropCommitsCommitProp
kazunori miyazawakazunori miyazawa2270.97%120.00%
herbert xuherbert xu516.13%240.00%
mathias krausemathias krause39.68%120.00%
patrick mchardypatrick mchardy13.23%120.00%
Total31100.00%5100.00%


static int esp_init_aead(struct xfrm_state *x) { char aead_name[CRYPTO_MAX_ALG_NAME]; struct crypto_aead *aead; int err; err = -ENAMETOOLONG; if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) goto error; aead = crypto_alloc_aead(aead_name, 0, 0); err = PTR_ERR(aead); if (IS_ERR(aead)) goto error; x->data = aead; err = crypto_aead_setkey(aead, x->aead->alg_key, (x->aead->alg_key_len + 7) / 8); if (err) goto error; err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); if (err) goto error; error: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu13791.95%240.00%
kazunori miyazawakazunori miyazawa96.04%120.00%
mathias krausemathias krause21.34%120.00%
patrick mchardypatrick mchardy10.67%120.00%
Total149100.00%5100.00%


static int esp_init_authenc(struct xfrm_state *x) { struct crypto_aead *aead; struct crypto_authenc_key_param *param; struct rtattr *rta; char *key; char *p; char authenc_name[CRYPTO_MAX_ALG_NAME]; unsigned int keylen; int err; err = -EINVAL; if (!x->ealg) goto error; err = -ENAMETOOLONG; if ((x->props.flags & XFRM_STATE_ESN)) { if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "%s%sauthencesn(%s,%s)%s", x->geniv ?: "", x->geniv ? "(" : "", x->aalg ? x->aalg->alg_name : "digest_null", x->ealg->alg_name, x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) goto error; } else { if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "%s%sauthenc(%s,%s)%s", x->geniv ?: "", x->geniv ? "(" : "", x->aalg ? x->aalg->alg_name : "digest_null", x->ealg->alg_name, x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) goto error; } aead = crypto_alloc_aead(authenc_name, 0, 0); err = PTR_ERR(aead); if (IS_ERR(aead)) goto error; x->data = aead; keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); err = -ENOMEM; key = kmalloc(keylen, GFP_KERNEL); if (!key) goto error; p = key; rta = (void *)p; rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; rta->rta_len = RTA_LENGTH(sizeof(*param)); param = RTA_DATA(rta); p += RTA_SPACE(sizeof(*param)); if (x->aalg) { struct xfrm_algo_desc *aalg_desc; memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); p += (x->aalg->alg_key_len + 7) / 8; aalg_desc = xfrm_aalg_get_byname(x->aalg